The present invention relates to a tire building machine for the preparation of pneumatic tire blanks. The machine includes a building drum to accommodate tire plies and a pressing roll cooperating therewith. Tire building machines for bias ply as well as belted tires and for dual or single stage tire building are conventionally provided with various ply suppliers and other devices for introducing and treating the individual components of the blank. Usually, each tire component is associated with specially structured treatment devices, for example, several ply applying rolls, stitching rolls, pressing rolls, splicing rolls and the like. Yielding pressing rolls are made of a foamed material and do not permit an adjustment or control of the pressure along the width and circumference of the blank.